The idea to present Karlheinz Essl's Lexikon-Sonate at the Banff Centre
for the Arts emerged from my own compositional work carried out this far
in the context of my residency in the Centre's Music and Sound Program.
My interest in exploring alternatives to the presentation of music in the
traditional concert situation, led to the conception of my music installation
project Camera musica, for which I am currently realizing the first
sketches at the Centre. In the context of this project, the work of Karlheinz
represents an important reference point for me.

In 1992, when Karlheinz was commissioned to write a piece for IRCAM (the
music department of the Centre Georges Pompidou in Paris, and my place
of employment), he started to use IRCAM's MAX program to reformulate and
extend the compositional strategies he developed before in his own LOGO-based
computer-aided composition environment. Having already cooperated with
Karlheinz on several occasions since the time of our student days in Vienna,
it was only natural that we had an intense exchange of ideas concerning
computer-aided composition during his time in Paris. At this time he also
started to develop his Real-Time Composition Library, a set of MAX program
modules on which the Lexikon-Sonate is based, and to which I contributed
some of the very early and basic concepts. For my music installation en
face (presented at the 1993 Mediale Festival in Hamburg) I developed
a set of programs inspired by our cooperation in Paris, but tailored towards
my own compositional requirements.

Since then we have not had the opportunity to collaborate again and it
was only here at the Banff Centre that I found the time to return to the
ideas we exchanged in 1992. This is why I started to analyze the Lexikon-Sonate,
one of the main pieces Karlheinz realized with the Real-Time Composition
Library. And since the Banff Centre owns a player piano, I had the chance
to directly experiment with the MAX program that represents the composition.
This program offers many different ways to influence the unfolding of the
music - from a very rudimentary level as presented in this installation,
to the most advanced possibility to extend the composition by adding new
modules to it. While exploring the piece in various ways, I also adapted
it to the particularities of the Centre's instrument, a Yamaha Disklavier
upright piano. The original version of the piece was premiered on a Bösendorfer
SE Grand Piano at the Austrian Radio during a life-broadcast in Vienna
in 1994. In the course of this performance, the radio audience could influence
the development of the piece by calling in to the radio station.

The decision to present the Lexikon-Sonate in the form of an installation
is my response to some of the many questions this piece raises for me.
In question are the classical concepts of music composition, presentation,
distribution, and perception. Thus, it does not appear evident to me that
the classical concert situation is the ideal context to present music of
such a kind. Especially the absence of a performer, the general allure
of the music and the possibilities to affect its evolution, almost call
for a presentation in an installation. The openness of the installation
situation - listeners may come and go as they like - finds its correspondence
in the openness of the music, which has no beginning nor end. I confronted
Karlheinz with the idea of presenting his piece in an installation at the
Centre and his enthusiastic response motivated me to share this experience
with the community of artists here. I chose a very simple and informal,
yet carefully arranged situation. I consider this installation an appropriate
context to display the piece, as well as a good opportunity to provoke
discussions about it.

From a compositional point of view, the most important particularity of
the Lexikon-Sonate is probably that it is not presented in a traditional
music score - a text to be interpreted by a performer - but that it manifests
itself as a computer program - a text to be executed by a machine. Thus,
in composing this piece, Karlheinz was not concerned with scoring the music,
but with devising a set of rules or mechanisms (a kind of meta-composition)
which describe the overall development, as well as the detailed articulation
of an infinite stream of piano music. Instead of writing one piece, Karlheinz
created a model which describes and is capable of producing an unlimited
amount of intimately related pieces - the proliferation of an idea. Each
performance of the Lexikon-Sonate displays only a particular fragment of
an irreproducible whole. Although not even Karlheinz will ever hear his
own piece entirely, the possibilities of its unfolding were present in
his imagination when he composed it.The version of the Lexikon-Sonate presented
in this installation consists of 15 independent music generating modules.
Karlheinz writes the following about these modules: "Each module generates
a specific and perceptually characterized musical output due to a certain
compositional strategy applied. A module represents an abstract model of
a certain musical behavior. It does not contain any pre-organized musical
material, but a formal description of it and the methods applicable to
it. The idea of 'autopoiësis' - material organizing itself due to
specific constraints - plays an important role. By using different random
generators which are controlling each other (which from a 'serial' perspective,
form a scale between a completely deterministic and a completely chaotic
behavior), new variants of the same model are generated. Variants may differ
dramatically from each other, although they are always recognizable as
'instances' of the given structural model."

The different modules are combined in such a way that always three of them
are operating at the same time, but with different significance. There
is always one module which forms the background for another one performing
in the foreground and there is a third one with medium importance assigned
to it. The possibility to influence the development of the piece (interact
would be too strong of a word, since it implies action and reaction, both
of which require intention, which, in my opinion, can hardly be expected
from a computer) is reduced in the installation to replacing the oldest
of the three modules by a new one when pressing a foot pedal. The modules
currently operating are displayed on the screen of the computer controlling
the player piano. If the foot pedal is not pressed for a certain time,
the piece will start to change state autonomously in order to avoid a structural
suspension of the music.

For more information concerning the Lexikon-Sonate, the Real-Time Composition
Library or other aspects of Karlheinz' work please refer to the his Word-Wide-Web
home page (http://www.ping.at/users/essl/index.html) or contact him via
email (essl@ping.at).

Biography of Karlheinz Essl

Karlheinz Essl was born in Vienna in 1960. He studied at the Wiener
Musikhochschule with Friedrich Cerha (composition), Dieter Kaufmann (electro-acoustic
music), and Heinrich Schneikart (double bass). He also studied musicology
at the University of Vienna and wrote his doctoral thesis on "Das
Synthese-Denken bei Anton Webern" (1989).

As a double bass player, Karlheinz Essl has played in different ensembles
of chamber music, jazz, and experimental music. His working with computers
and a prolonged occupation with the poetics of serial music, have been
a formative influence in his compositional thinking. Between 1992-93 he
was working on a commission at IRCAM (Paris).

Since 1990 he has been composer in residence at the Darmstädter Ferienkurse
für Neue Musik. Currently he is teaching computer music at the Studio
for Advanced Music Technology of the Anton Bruckner Conservatory in Linz/Austria.

Essl's works have been performed at the most important music festivals
by ensembles like the Arditti Quartet (London), Ensemble Modern (Frankfurt),
Nieuw Ensemble (Amsterdam), Ensemble InterContemporain (Paris) and Klangforum
(Wien).